I don't think that's screen tearing. That looks like some texture abnormality in the graphics rendering.
If you are getting that on multiple games but not all, I would say the graphics part of your PS3 might be faulty or failing. The only advice I can think of is to turn off the PS3 via the rear power switch, or unplug the unit overnight. I doubt it would do anything, but sometimes strange things have a way of working themselves out -- albeit usually temporarily.
"My advice: don't spend money on therapy. Spend it in a record store." – Wim Wenders